Bifurcating Coral

Syringopora species from the Carboniferous of Cumbria is a bifurcating coral.  It grows upwards forming an ever extending set of coral stems that diverge into two stems at frequent intervals.  Cross branches are secreted to bind the coral structure together.

These types of corals are found throughout the Palaeozoic Era in many similar forms.  Without restrictions, the growth pattern would lead to a large domed coral with living corals at the top edge.  In a reef, the developed shape of the structure would be less even.

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Soft Mud Preservation

Occasionally, very fragile fossils are found that are seldom recoverable.  Here we see two specimens of the Jurassic Ammonite Dactylioceras preserved in soft mud sediment of Jurassic Age.  This sediment from near Holwell in Leicesterchire, UK, contains ammonites and belemnites which are preserved as soft muddy infill in a soft muddy shale.  The specimens are quite dry where the shale is exposed to the weather and are easily eroded to dust.  Deeper in the sediment they are soft and pliable and can be crushed like plasticine models.  This specimen has been treated with a binding agent to preserve the shape and structure.

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Terabratulid

Brachiopods like Stroudithyris are common throughout the Inferior Oolite.  They are a type of  Brachiopod often referred to as Terabratulids.  This specimen is from near Stroud in Gloucestershire, UK.

The scar at the top rear of the lower or pedicle valve is where the pedicle attached.  This was a moderately thick stem that arched out from the back of the valve and anchored the brachiopod to the sea bed, rocks or whatever happened to be available when it started to mature.  The smaller upper valve is called the brachial valve.

Devils Toe Nail

Gryphaea arcuata is a common Jurassic rock oyster.  This bivalve is well-known amongst fossil collectors for its common name of “Devils Toe nail”.  This fossil is found throughout the Lower Lias and is typically found around Dorset, Gloucestershire and Yorkshire.

Worn and broken specimens are often found in more recent gravels which have been derived from eroded rocks from the Lower Jurassic Sediments, so there may be specimens in the gravel on nearby driveways and gardens.

Polished section

Fossil corals have been around since the earliest life forms with hard parts, in one form or another.  This coral is Lonsdeleia species, a type of rugose coral from the Carboniferous.  The specimen is a polished block from the Namurian rocks of Cumbria.  Similar fossils can be found throughout Shropshire and into the Welsh Boarders.  his coral is probably Lonsdelia floriformis, but it is difficult to be sure of the classification as the very top of the fossil structures are missing in this section.

Productus

Productids are flatish brachiopods from the Palaeozoic Era.  This one which is an impression about 2cm wide is Productus productus from the Nenthead Quarry in Cumbria, UK.  The fossil is Vesian/Namurian in age and can be found throughout the UK in rocks of this age.

This fossil is preserved as an impression of the outer shell in a shale sediment.  only the surface details on one side of the animals shell can be seen.

Spinatum Zone Brachipods

T. tetrahedra

Brachiopods were small clam like shells with a spiral structure between the valves.  As mature shells they would be anchored to the sea bed by a small stype that enabled them to float above the substrate and filter feed in the flowing water, often in shallow seas.  Tetrarhynchia tetrahedra is a common brachiopod from the Lower Jurassic.  These 3 specimens are from the quarry at Holwell near Melton Mowbray in Leicestershire.  They are often found by the dozen when they are in situ.